All the music set to be played at this Sunday’s Bangor Symphony Orchestra concert at the Collins Center for the Arts was composed by Americans. But among the familiar names such as Gershwin, Copland and Barber, there’s a name unique to Bangor: Kay Gardner, a musician, composer and spiritual leader who died in 2002.

Gardner’s composition, “Quiet Harbor,” will be performed Sunday, as well a new composition by BSO music director Lucas Richman, “Isaeum,” written in Gardner’s memory and commissioned by Deighan Wealth Advisors in cooperation with Gardner’s daughters Jenifer Wilson and Juliana Smith.

“The music one leaves behind is as informative as the stories one hears,” said Richman. “She was a remarkable woman with a big personality, and I hope I’ve been able to bring that forth in what I’ve written.”

Gardner was born in 1941 in New York, and almost immediately took to music. She studied performance and composition at the University of Michigan and at State University of New York at Stony Brook. In the 1970s she started her own record label, Wise Women Enterprises; she was also among the earliest openly gay musicians of her time and was a member of the lesbian feminist band Lavender Jane in the early ’70s.

For most of her career, she aspired to be a conductor, but found it nearly impossible, as a woman, to find a position in a still male-dominated field.

“She was always encouraging women, and people in general, to feel comfortable making music and expressing themselves,” said Wilson, who still lives in Bangor. “They could be completely tone deaf, and she’d bring it out of them. She really believed in the healing power of music, and that everyone could find a way to express themselves.”

Her focus later turned to composing, and over the years, she wrote works large and small, from the eight part “A Rainbow Path,” to “Veriditas,” inspired by the medieval composer Hildegard von Bingen and composed around the Fibonacci sequence of numbers.

Gardner moved to Maine in the 1980s, where, among other things, she founded the women’s vocal group Women With Wings, and the Temple of the Feminine Divine, a spiritual organization located on Central Street in downtown Bangor — both are still active. She was also the music director at the Unitarian Universalist Church on Park Street until her death in August 2002, and she was awarded an honorary doctorate and the Maryann Hartmann Award from the University of Maine. She was an accomplished flutist and composed music throughout her life. One of her compositions, “Lament for Thousands,” written in the wake of the Sept. 11, 2001, terror attacks, was given its premiere by the BSO in 2002.

“She was a strong person, very opinionated, and always felt that women were underrepresented in the classical music world,” said Wilson. “But she was grateful to have her music performed back then, and I know she’d be grateful to hear what’s being performed at this concert.”

Richman’s piece, “Isaeum,” reflects upon Gardner’s life and work, and her devotion to the Egyptian goddess Isis, of whom she was a priestess. “Quiet Harbor,” Gardner’s own composition, was inspired by Maine’s coast.

“It’s impressionistic, in a way. It sounds like the murmurs of the ocean,” said Richman. “It’s a very tranquil melody, with an arc to it. It’s a moment in time. It’s really very lovely.”

In addition to Gardner’s work, there are three other pieces set to be performed. George Gershwin’s big, brash beauty of a symphonic piece, “An American in Paris,” will be performed for the first time in decades by the BSO, in one of the largest iterations of the symphony in recent years. Also set to be performed is Aaron Copland’s “An Outdoor Adventure,” a brief and invigorating piece by the mid-20th century composer, and Samuel Barber’s Violin Concerto, featuring soloist Sheryl Staples.

Staples is the principle associate concertmaster for the New York Philharmonic, a position she has held since 1998. She’s also a longtime associate of Richman’s, who has known her since she worked in the mid-1990s with the Pacific Symphony in Orange County, California.

“It’s a treat to see her and work with her, and we’re really thrilled she’s able to come up this time. We’ve wanted to have her a number of times and it’s finally worked out,” said Richman. “She’s a very soulful player. Her sound is rich and vibrant, which is perfect for the Barber concerto. It really sings.”

Sunday’s concert begins at 3 p.m. at the Collins Center for the Arts; tickets are $19 to $43 and are available online at collinscenterforthearts.com and at the CCA box office. For information, visit bangorsymphony.org.